


Defenders of the Universe

by psychobabblers



Category: DCU, Justice League & Justice League Unlimited (Cartoons), Voltron: Legendary Defender
Genre: AU, M/M, Team as Family, the justice league fights giant space monsters in a giant space robot, this is going to be very campy
Language: English
Status: In-Progress
Published: 2017-10-26
Updated: 2017-11-08
Packaged: 2019-01-23 09:19:06
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,064
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12504104
Author URL: https://archiveofourown.org/users/psychobabblers/pseuds/psychobabblers
Summary: His first mistake, Bruce thought resentfully, was trusting Green Lantern when he’d called the fledgling League for an emergency meeting at some random desert in the middle of nowhere. But there’d been a spark of, well something, in his tone, and Bruce had been just curious and just concerned enough to fire up the jet. Which was why he was now in this predicament, squished into the cockpit of a giant robot lion with him, Wonder Woman, Flash, and Cyborg.A Voltron: Legendary Defenders AU





	1. The Legend Begins

His first mistake, Bruce thought resentfully, was trusting Green Lantern when he’d called the fledgling League for an emergency meeting at some random desert in the middle of nowhere. But there’d been a spark of, well something, in his tone, and Bruce had been just curious and just concerned enough to fire up the jet. Which was why he was now in this predicament, squished into the cockpit of a giant robot lion with him, Wonder Woman, Flash, and Cyborg. And the Lantern claimed he had lost control of the robot.

Even worse, although they’d destroyed the massive alien warship approaching Earth - the Lantern wasn’t that bad a pilot - they were now stuck in a wormhole whose exit was anyone’s guess.  
Bruce hated guessing. At least without any sort of reliable data.

Wherever the lion was taking them though, it was going to be far away, further than any humans had traveled before. He had caught a glimpse of the moons of Pluto flashing by while they'd been fighting the alien ship, which was still hard for him to believe. To travel so far in so short a time...this alien technology was incredible and seemed to have an artificial intelligence beyond anything they had developed on Earth. Though he drew the line at the Lantern's claim of a magical mental link between him and the giant robot lion.

“Guys,” the Green Lantern said tensely, “I think we’re about to exit the wormhole.”

“Do you know where it’s taking us?” Cyborg asked, frustration edging his voice. He hadn’t been able to integrate with the robot, to his chagrin.

“It’s stopped communicating with me.”

“Wherever we land, whoever is out there, we will face them head on,” Diana said fiercely.

Bruce said nothing, just watched the dizzying swirls of the wormhole as it grew brighter and brighter until it was almost painful. And then just as suddenly as they had entered, they were elsewhere. It was an elsewhere with clear blue skies and soft wisps of cloud, rolling green hills and snow capped mountains. For a split second Bruce considered the possibility that this was some remote place on Earth, or perhaps a different time on Earth. But the unmistakable _alienness_ of the place, despite its apparent resemblance to Earth, put that idea to rest. He would have to get Green Lantern to give him some readings on this place via the lion later.

“Look,” Diana said, pointing. “A castle.”

If Bruce had any doubts about this place being alien, the sight of the castle was enough to put them to rest. It was an incredible feat of engineering, seemingly hewn out of a massive crystal with a main spire and several other smaller ones arranged around it, and perched on the edge of a cliff on almost dainty “legs”. Or, they could be engines. He wondered if it was possible that this castle was actually a ship.

The lion brought them to the courtyard of the castle and lowered its head to let them step out of the cockpit before letting out an earth shattering roar. The massive crystalline doors swung smoothly open without even a whisper.

The League stared at the vast darkness within.

Green Lantern broke the silence by elbowing Flash.

“Looking a little green there,” he said with a smirk.

“Fuck you,” Flash replied without heat. “Let’s just go inside. Maybe something will kill us before Green Lantern tries to fly that thing again.”

It was definitely not as ominous as Flash made it sound once they stepped through, trying not to wonder why such a massive doorway was necessary. Possibly it was just so the lion could fit, Bruce decided. It did seem to belong in this place. The entire place was massive, with ornate columns and delicate crystal structures. As they walked, the castle gamely lit the way for them until they arrived at a circular room with some upright pods that could comfortably fit an adult human male. Bruce stepped up to one and examined it. Cyborg joined him.

“What do you think it is?” he asked.

“Possibly a cryopod.”

“So you think there could be someone inside it. Someone alive?”

“Possibly,” Bruce sais, mind whirling with the possibilities. “We need to find a control panel.”

“Are you sure this is a good idea?” Flash asked nervously. “We don’t know if they’re gonna be friendly to intruders, especially if they’ve been sleeping for awhile.”

“If this is a cryopod, they’ll probably come out groggy, right?” Lantern said. “The lion brought us here for a reason. I think this is it.”

As if it had been waiting for them to come to a decision, the door of the cryopod retracted - Bruce hadn’t even seen an outline of a door - and a man toppled out, as icy mist poured from the machine. Closest to the door, he reached out instinctively to catch him and ended up almost knocked over. The man must be pure muscle.

“Wha?” Startlingly blue eyes blinked open at Bruce with confusion, and that was all the warning he got before he was lifted, and a blade was at his neck and the man’s back was to the wall, facing out at the rest of the League. “Who are you? Where is my father?”

Bruce held himself still as the very sharp blade pressed harder against his throat, deciding not to break out of the hold for now. The man seemed disoriented and confused, but not necessarily an enemy.

“We are the Justice League of planet Earth”, Diana said, stepping forward slightly. The man tightened his grip on Bruce in reflex and she stopped.

“Earth?” He said wonderingly. “Rao, how much time has passed? How did you get here?”

“A blue robot lion brought us here,” Bruce said carefully. “Perhaps you can release me and we can figure out what’s going on.”

“The Blue Lion brought you here?” The man let him go at that and stepped over to a fixture as Bruce backed out of range. It lit up under his touch, humming slightly with energy, spitting out information faster than a human could process.

“Woah,” Cyborg muttered.

“It’s been...” the man said, looking stunned. “It’s been 10,000 years.”

“I’m sorry,” Diana said softly.

He seemed to square himself at her words, turning to face them, a look of unspeakable loss in his eyes. “The castle informs me that my people and my planet have been destroyed by Darkseid, against whom my father died fighting. My father is the one who built the lions, including the Blue Lion that brought you here, and scattered them to the winds to keep them out of Darkseid’s hands.”

He made a gesture and the computer projected a 3d view of the galaxy onto the room. “Purple shows what he has already conquered.” Almost everything was colored purple.

“Wait... where’s Earth in all this?” Flash asked.

The man zoomed the map out and a tiny dot started flashing. It looked frail surrounded by the tide of purple.

“Did you know about this?” Flash asked Green Lantern.

“No, the Guardians never told me about this.”

“A Lantern? From Earth? Your species has come far in 10,000 years,” The man said.

Bruce bristled a little at the patronizing words, but the man didn't seem to notice.

“So where do we fit into all this? And where do you?” Wonder Woman brought them back on track.

“I am Kal-El, last of the planet Krypton and the Kryptonian civilization. We had been leading the war effort against Darkseid’s rise to power. He has been searching for the lions of Voltron all this time. But the lions choose their pilots, and one of them has already chosen one of you. Once the rest of you have your lions, you will be able to form Voltron, the most powerful weapon in the universe, the only thing that can stop Darkseid.”

Wonder Woman stepped forward, eyes flashing. “Where do we start?”

Kal waved his hands again and a massive black robotic Lion was projected in front of them.

“First we have to collect each lion. My father connected my essence to that of the lions, which will help us find where each one is located. The Black Lion is in the castle itself and can only be released when the other four are present. As the head of Voltron, it takes a true leader to pilot. It is the most difficult to master and demands the most from its pilot.” Kal pointed at Bruce. “You will pilot the Black Lion.”

“Batman?!?” He heard Green Lantern mutter to Flash, who elbowed him sharply.

A smaller red lion appeared, eyes flashing yellow, mouth open in a snarl.

“The Red Lion,” Kal continued, ignoring the discontent. “Fiery and spirited, its pilot will have to earn its respect. It will form the right arm of Voltron.” He pointed at Wonder Woman. “You will pilot the Red Lion.”

A green lion joined the red and the black.

“The Green Lion requires a pilot of intellect and curiosity. It forms the left arm of Voltron. You will be its pilot,” Kal said, pointing to Cyborg.

A hulking armored Yellow Lion appeared next.

“The Yellow Lion has a protective spirit, and its pilot must also have it in kind. It forms one of the legs of Voltron.” He pointed at Flash. “You will pilot the Yellow Lion.”

A holographic image of the Blue Lion who had brought them here appeared. “And the Blue Lion has already found its pilot.”

He made another gesture and the five lions came together and became a giant humanoid robot. It should have looked ridiculous but somehow it didn’t. “We have to find these lions before Darkseid does.”

“Wait,” Bruce said. “This is a lot to take in at once. How do we even know if we can trust him?”

Kal locked his jaw and glared at him. “Weren't you listening to what I said? Didn't you see this map? Darkseid has almost conquered the entire known universe. My people and planet were destroyed and my father, one of the greatest warriors and minds in the galaxy, was murdered by this monster. Your planet will share the same fate if we do nothing!”

“Batman,” Wonder Woman said. “I believe that he is trustworthy, but if you need evidence, the lasso shows that all he spoke was truth.” She held the golden lasso up where the end still draped over his foot. Everyone else nodded in agreement.

“Has everyone forgotten that his lion captured us and brought us halfway across the universe?” Bruce growled.

Kal opened his mouth to retort and the air was suddenly split with the sound of klaxons and flashing red lights. He quickly put his hands back on the control panel, eyes flickering over the jumble of symbols. “There's an Apokalips battle cruiser headed right for us! It's a day out at most.” He looked straight at Bruce. “Better decide what you want to do quickly.”

Bruce folded his arms, a little irked at how quickly the rest of the League had gone along with Kal. But if Kal was right, and there was a battle cruiser headed for them, they should at least grab the lions before another party did.

“Fine,” he said. “We'll go grab the lions.”

“Good to have you with us,” Kal smiled. “Batman, is it? You can go with – ”

“— Cyborg.”

“Yes, Cyborg, and take one of the shuttles to pick up the Green Lion over here,” he pointed to a planet.

“You two,” he pointed at Flash and Green Lantern, “will take the Blue Lion to get the Yellow Lion from here. I can open portals for you to your respective planets.”

“Unfortunately, I'm not sure where the Red Lion is. I can't seem to sense it,” Kal said, looking at Wonder Woman. “You should wait here and take the other shuttle if I manage to locate it.”

“Good hunting,” she said to the rest of them.

* * *

“I thought you said the cruiser was a day out!” Bruce gritted his teeth and tried not to too obviously shove the alien presence from his mind while still managing to fly his lion.

“I said at most,” Kal said. “Focus on flying and bonding with your lion.” The window that had popped up next Bruce's seat showed him looking very stressed out as he fired up the Castle's defenses against the swarm of starcraft.

The lion seemed to be resisting everything he was doing. The last few shots had been much too close for his liking. “Stop fighting the lion,” Kal said, popping up again even though Bruce had closed the window. Bruce growled under his breath.

“Where I come from, there aren't any mystical bonds between giant robot lions and humans.”

“Everyone else seems to be doing okay,” Kal snapped at him. “You have to trust your lion. And form Voltron!”

“Come on, cat,” Bruce said, feeling slightly silly. “We both want the same thing. Work with me here.”

Was it his imagination or did the controls feel just a little less resistant?

He tried to relax a little and focus on the ships, the enemy fighters, the position of the other lions, his teammates, the mission. He needed to destroy the fighters before they destroyed the Castle. He needed to help fight Darkseid, despite the doubting words he had thrown at Kal. Batman was pledged to fight injustice and stand against people who sought to do harm. The lion seemed to sing now as he flew it, and why had he ever thought it was difficult to fly?

It handled more easily than anything he had ever flown before, seeming to predict what he wanted before he even knew himself, and leapt to do it. The enemy fighters crumpled under the onslaught of the lions. But more just kept coming, pouring out of the belly of the great battle cruiser hovering at the edge of the atmosphere.

Suddenly, the cruiser fired a massive bolt of energy at the Castle. The shields hummed with distress, but held. The fighters took the chance of shock to press the advantage, driving the lions back.

“There's so many of them!” Flash shouted. His lion was, ironically, the slowest of them all, but compensated for it with heavy shields. It was obvious he was having to get used to the different fighting style.

“You have to form Voltron!” Kal said, popping into view once more. “The Castle's shields won't hold much longer.”

“How do we do that?” Wonder Woman asked. She was flying her lion as if she had been born to do it – apparently having had no problem earning its respect as Kal had warned.

“We have to think and move as a team,” Bruce said quietly, thinking about his interactions with the Black Lion. “We are the Justice League, we originally came together to defend Earth, because we knew we would be stronger together than apart. We are the only thing that stands between Earth and destruction. We will form Voltron!”

At those words, there was a strange lurching sensation, and for a moment Bruce lost all orientation, as the lions came together and the five were suddenly one giant robot.

“Woah,” Cyborg said.

They leapt up and deflected another energy blast from the cruiser before punching it out of the sky. One swipe of its arm, Wonder Woman's battlecry over the comms and most of the fighters were downed as well. It was, Bruce reflected, very easy to destroy giant overpowered enemies when you yourself was driving a giant robot.

“Great job,” Kal said, smiling on the screen.

“And nice speech, Batman,” he added in their private window, and his smile was as bright as the sun, so contagiously joyful that Bruce almost smiled back as he guided his lion back into the Castle's courtyard, the rest of the League landing around him.


	2. Chapter 2

“Why didn’t you just follow the goddamn plan?” Bruce said furiously as he stormed onto the command deck, ignoring the exchange of looks between the rest of the team.

“I had to do something,” Kal said calmly.

For some reason that inhuman calm in the face of his anger sparked Bruce’s temper even further.

“You were already doing something! You were covering those Opularians’ escape! They could’ve all died because you came haring off to the rescue!” _You could have died too_ , he was about to say, but he was interrupted.

“But they didn’t,” Kal said, still calmly, still indifferent to the fact that he had just casually disregarded a key tactic that they had hammered out earlier.

“You’re not invincible you know, just because you fly some crazy overpower castle.”

“I know,” Kal said, a hint of irritation in his eyes, though his voice betrayed none of it.

Dimly Bruce was aware of Flash — Barry — muttering that he was going to go take a shower and then zipping off before anyone had a chance to respond. “What was I supposed to do though, let them blow you to bits?”

Bruce glared. “I had it under control.”

“If that’s what 'had it under control' looked like, I don’t want to see out of control,” Kal snapped.

Bruce briefly considered benching the person who had taught Kal how to do air quotes. “I can take care of myself,” he said tightly.

“Your Lion froze!” Kal said incredulously. “There was no way you were going to be able to get out of that alive.”

“This isn't about me,” Bruce said mulishly. This was why he worked solo. “This is about you being unable to stick to the plan. The plan that you agreed to! You can't just break strategy on a whim.”

Kal was trying hard not to roll his eyes, Bruce could tell. Someone was teaching Kal too many Earth customs better left on Earth. “Yeah, and you've never done that,” he said, voice heavy with sarcasm.

There was a long silence after that where they both stood there and struggled to find a way to extricate themselves from the argument. “I'm going to Gotham. Patrol,” Bruce said finally, drawing his dignity about him like a cloak. The others had slipped out after Flash at some point and they were alone in the room.

Kal looked at him closely then, something like concern in his eyes. “That was a rough mission. Maybe you should get some rest.”

“Maybe you should,” Bruce shot back, and it wasn't just to be difficult. The man looked exhausted. It was difficult to tell at a glance, because of the strange perfection of his features, but after spending so much time with him developing the strategic direction of their fight against Darkseid, he'd come to know Kal well enough to recognize it. If he took the time to actually look. Bruce chided himself for not recognizing it earlier. Kal was overworking himself, which could be a disaster if his concentration failed in the field.

It'd only been a few weeks since he'd been unfrozen, only a few weeks since he'd learned of the destruction of his planet and his people, and the death of his family. Bruce felt a twinge of empathy. He closed his eyes, and for a moment it felt like he was just a boy again, staring at his parents' graves through the torrential rain. Kal had lost much more than that. There was just one thing to do – for the good of the Voltron Alliance, and the universe.

“Come with me to Gotham,” Bruce said before he could second guess himself. “You can stay at my place tonight.”

Kal looked at him, his expression unreadable. “I thought you didn't want any help in Gotham?”

“Not on patrol,” Bruce clarified. “Just thought, you might want to see where us Paladins came from. I can show you around the city, if you'd like.” He must be more tired than he thought, if he thought Kal would actually accept. All they had done since they'd met was argue. He hadn't ever shown an ounce of empathy to the other man, that he understood something of what he must be feeling. The offer hung in the air heavily.

Bruce let out a small breath and turned to go.

“Okay,” Kal said quietly, and Bruce froze.

“Okay?” Bruce repeated, surprised.

“I'll come with you to Gotham.”

Kal opened a portal to the Cave almost hastily, as if trying to do so before they both changed their minds, and then they were through. Kal was standing in Gotham. Because Bruce had invited him there. For a sleepover.

He didn’t have time to facepalm because Kal was wandering around looking curiously at the monitors and bits of gear. And he really had to get out on patrol.

“You can stay here or upstairs while I'm out,” Bruce said, half awkwardly and half absentmindedly, thinking about the route he’d take tonight and which locations were most likely to yield some clues for that case he was working on -

“I’m fine here,” Kal said.

Later Bruce would feel a little alarmed at the fact that he was okay with Kal just sitting in the Cave while he was away, poking into who knows what. He'd drawn the cloak of solitude around himself for so long, and only Alfred had been able to see inside. But here was Kal, who barely knew him, stripping it away so easily that Bruce barely noticed. But now he just grunted in distracted affirmation, stripping off the Voltron uniform and donning the Batman armor instead.

Patrolling Gotham always gave him some sense of peace, oddly enough. Sure it was often broken by spurts of violence and the wail of sirens but there were also long stretches when it was just him and his dark, beautiful city. Slipping along the familiar alleys and rooftops that he could grapple off of in his dreams, listening for people that he could help, or clues to unravel a bloody puzzle, it was a welcome respite from the universe spanning strategic decisions he’d been having to make as part of Voltron. It was good to hone in on the details.

Kal looked up from what he was reading when Bruce finally returned, sweaty and leg aching a little from where some thug had gotten a hit in with a crowbar. He was lucky; it’d only been a glancing blow.

It looked like Alfred had been down to greet Kal while he was out on patrol, since he had half a chocolate chip cookie in his mouth, and more cookies on a plate and a mug of something hot and steaming next to him. A tacit sign of Alfred’s approval.

“I see you’ve met Alfred,” he said by way of greeting.

“Yes,” Kal said, smiling. “He offered me some Earth food. It's delicious!”

“Alfred's cookies are the best I've ever had,” Bruce said, starting to take the armor off piece by piece. “If you like sweets, you should try his apple pie and ice cream.” He stifled a hiss of pain as he gingerly maneuvered the leg piece that had absorbed most of the blow. As he'd thought, there was no blood, but the skin was already starting to turn a mottled discoloring. It'd be fine in a few days. He reached for the sweatpants on the rack and brushed warm skin instead. He looked up, uncharacteristically startled.

Kal was holding out the clothes for him, eyes fixed on the vicious bruise, but he said nothing.

How had he moved so quietly that Bruce hadn't noticed? He shook his head, feeling the exhaustion creeping in. He dressed quickly to protect himself from Kal's gaze, not meeting his eyes.

“Time to sleep, at least for me,” he said brusquely.

“I'm tired too,” Kal admitted.

“I'm sure Alfred's prepared a bedroom for you by now.”

Sure enough, Alfred appeared when they stepped out through the secret door into the Manor. “I can show you to your room now, if you would like to retire.”

Bruce allowed himself the luxury of auto-piloting in the safety of his home, letting the even conversation between Alfred and Kal fade into the background. He was vaguely aware of bidding them good night and barely managing to get the covers over himself before he was asleep. His last thought was that tomorrow, he'd show Kal around Gotham.

 

**Author's Note:**

> I thought a long time which lions to put everyone in, and struggled the most with Clark and Bruce... But then I realized Clark was obviously Princess Allura and after that everything worked out semi-okay =) Also, I'm thinking of this as more of a series of one-shots than a whole overarching fic, just so you're aware upfront!
> 
> Black Lion - Batman  
> Red Lion - Diana  
> Yellow Lion - Flash  
> Green Lion - Cyborg  
> Blue Lion - Green Lantern


End file.
